Arc-lamp.



W. A. DARRAH.

-ARC LAMP. APPLICATION FILED JAN 24, I914.

Patented Apr. 30,1918.

ATTORNEY UNITED STATES PATENT ora ion.

WILLIAM A. DARRAH, OFWILKINSBURG, PENNSYLVANIA, ASS TGNOR TO WESTING- HOUSE ELECTRIC AND MANUFACTURING COIVIPANY, A CORPORATION OF PENN- SYLVANIA.

Application filed January 24, 1914. Serial Nd. 814,019.

To all whom itmay concern:

Be it knownthat I, WILLIAM A. DARRAH, a citizen of the United States, and a resident of WVilkinsburg, in the county of Allegheny and State of Pennsylvania, haveinvented a new and usefullmprovement in Arc-Lamps, of which the following is a'spe'ciiication.

My invention relates to arc lamps, and it has special reference to are lamps commonly known asflaming and luminous arc lamps which are of the non-focusing type. v

Inasmuch as electrodes used in lamps of the character above mentioned yield fumes and vapors which contain much suspended matter when consumed in the arc, provision must be made for withdrawing the fumes and vapors from the arc chamber either by an adequate circulating system communicating with the outer air or by causing them to condense and deposit upon portions of the lamp structure other than the surface of the arc-inclosing globe or the members comprising the feeding and regulating mechanisms of the lamp. To prevent a surplus of air from entering the arc chamber in order'to prolong the life of the electrodes and, at the same time, to provide means for overcoming the aforementioned difliculty, the arc is inclosed by a globe which is. closed at its bottom and communicates atits top with an airtight heat-radiating or condensing chamber. 7 Since it is particularly desirable to have as simple a mechanism as possible, nonfocusing arc lamps have been proposed in which the regulating or focusing mechanism has been ellminated, thereby conslderably simplifying the mechanical structure of the lamp. In non-focusing arc lamps, the arc travels either upwardly or downwardly, as the electrodes are consumed,by reason of the operation of the feeding mechanism. As a result, it is diflicult to maintain a clean inner globe which will permit passage, therethrough of the emitted light flux without undue absorption, irrespective of the position of the arc.

By means of my invention, I provide an inclosed flaming arc lamp of the nonfocusing type wherein the deposits resulting from the fumes and vapors evolved from the arc will not effect a material absorption of the emitted light flux. I

Another object of my invention is" to pro- ARC-LAMP.

Specification of Letters Patent. Patented Apr. 30, 1 918- vide anarc lamp which embodies the features enumerated above and which is adapt-' cd' for mounting upon a pedestal or post.

A further object of my invention is to provide an arc lamp adapted for post mounting which will be simple and inexpensive to construct, and, after having been installed, will have a satisfactory operating efficiency and an economy of electrode consumption and maintenance cost as favorable as in arc lamps heretofore constructed. I v

For a better understanding of the nature and scope of my invention, reference may be had to the following description and the accompanying drawing, the single figure of which is a view, partially in'elevati'on and partially in section, of an arc lamp that embodies a form of my invention.

Referring to the drawing, the arc which extends between the opposing and adjacent ends of alin'ed electrodes 1 and 2, is contained 'within an arc chamber 3 provided by an inclosing globe 4f, the chamber 3 being closed to preclude the circulation therethrough of atmospheric air. By means of an annular member 5 with which the globe l slidingly engages, a passageway 5 is provided, whereby the arc chamber 3 may communicate with an air-tight condensing chamher 6, walls 7 of which'are'made of heatradiating material with an exposed surface of large area relative to the cubical contents thereof. An outer globe S-of any preferred form substantially surrounds the arc-in'clos ing globe 4, thereby establishing a dead airspace 9 which is cut off from communication with the condensing chamber 6 and a mechanism chamber 10 by iinperforate members 11 and 12, respectively.

At the beginning of a trim, the upper el'ec' trode 2 is secured to a stationary holder 13, and the cooperating lower electrode 1 is disvosed in a recess formed in a movable holder 14 which is detachably secured to a vertical rod 15. The upper electrode 2 is preferably made with a comparatively large diameter and a comparatively short length which prevent the arc from advancing upwardly any substantial distance during the consumption of the electrodes. By this arrangement, the length of the upper electrode 2 will decrease very slowly as the electrode is consumed. thereby materially limiting the upward travel of the are, as the lower electrode more rapidly decreases in length. Of course, this modification approaches somewhat the result elfected by a focusing mechanism which continually retains the arc in a fixed position, irrespective of the lengths of the electrodes. As a result of using an upper electrode of the character above mentioned, the length of travel of the arc-inclosing globe t is materially decreased.

The arc-inclosing globe t engages a flanged portion 16 of the holder is, thereby furnishing an arc-inclosing globe that is closed at its bottom and precluding the accumulation of soot and powdered carbon upon the upper surface of the member 12 and the members contained in the chamber 10. It is desirable to have an upper edge 17 of the arc globe 4: formed to slidingly engage the tuner surface of the annular member 5 without undue friction. However, it is only essential that the joint between the globe 4: and the member 5 be close'enough to prevent the fumes and vapors generated by the are from flowing into the dead air space 9.

The feeding mechanism of the lamp, which is disposed in the chamber 10 located in the upper portion of a pedestal 18, comprises a rocking lever 19, a clutch ring 20, a core member 21 of an electromagnet 22, a dash pot 23, and a pulley 2a rotatably mounted upon the lever 19. The lever 19 is pivotally mounted upon bearings (not shown) secured to walls inclosing the chamber 10, and is provided with a central opening through which the rod 15 loosely. projects. To a downwardly extending member 25, which is rigidly attached to the lever 19, is pivotally secured the clutch ring 20 that is adapted to engage the rod 15 during the operation of the lamp When the electromagnet 22 is deenergized, the arcing ends of the electrodes abut against each other, and the clutch ring 20 occupies a position upon a horizontal seat 26, as shown in the drawing.

To draw the arc, the electromagnet 22 is energized from a' source of power (not' shown), thus causing the core member 21 to be drawn downwardly. The lever 19 is rocked to effect engagement of the clutch ring 20 with the rod 15 and raise a weight 27 which also performs the function of a piston member of the dash pot 23. As the rod 15 is drawn downwardly by reason of its engagement with the clutch ring 20, the arc is drawn between the opposing and adjacent ends of the electrodes 1 and 2. Inasmuch as the lamp shown is of the intermittent feed type, the arc is intermittently extinguished to permit the feeding operation of the lower electrode 1 to be performed. At the beginning of a trim, the upper edge 17 of the arc-inclosing globe t engages the annular member 5 near its lower dge 28, As the electrodes are consumed, and the eegaeo lower electrode 1 is intermittently fed up wardly, the arc and its inclosing globe 1 travel upwardly;

During the existence of the arc, the fumes and gases evolved therefrom. pass through the annular passageway 4* into the heat-radiating chamber 6 where they become cooled. Subsequently, these gases condense and deposit upon the walls 7, thereby maintaining the inner walls of the globe a substantially 7 free from deposits. As the position of the are relative to theglobe 4 does not change during th trim, very littlelight flux is absorbed by the deposits formed upon the globe surfaces remote from the arc. The soot and carbon particles which are too heavy to fiowwith the gases into the cham her 6 accumulate in the lower portion of the arc-inclosing globe 4; where they are retained, thereby preventing them from collecting upon the member 12 and depositing upon the members of the mechanism contrained in the chamber 10.

While I have disclosed only one form that my invention may assume, I do not intend that my invention shall be limited to this particular embodiment, as those skilled in the art will readily understand that changes may be made without departing from the spirit of my invention.

I claim as my invention:

1. In arpost-type arc lamp, the combination with a vertical supporting member having a chamber in its upper end, of a pair of vertically alined cooperating electrodes disposed above the supporting member, the

upper electrode being stationary, a feeding mechanism for the lower electrode disposed within the chamber, a condenser disposed above the electrodes and having a bottom opening therein, a tubular member disposed in the bottom opening, and an arc-inclosing globe mounted on the lower electrode to move with the same and to slidingly engage the tubular member to maintain a closed joint between the globe and the condenser.

2. In a post-type arc lamp, the combination with a support having a chamber in its upper end, of an outer globe disposed on the support, a hollow condenser having a bottom opening and resting on the outer globe, a tubular member disposed in the opening, a stationary upper electrode supported by the condenser, a movable cooperating lower electrode, a feeding mechanism therefor within the chamber of the support, and an inner arc-inclosing globe containing the lower electrode and supported by the feeding mechanism, the inner globe having a closed bottom and an open top slidingly engaging the tubular member.

3. In a post-type arc lamp, the combination with a support having a chamber in its upper end, of an outer globe disposed on the support, a hollow condenser having a bottom opening and resting on the outer globe, a tubular member disposed in the opening, a stationary upper electrode supported by the condenser, a movable cooperating lower electrode, a holder for the lower electrode disposed at the lower end of the same, an actuating rod in alinement with the lower electrode and engaging the holder, a feeding mechanism for the actuating rod, and an inner arc-inclosing lobe supported at its lower end by the holcir, the inner globe having an air-tight closure at its point-of connection to the holder and an open top slidingly engaging the tubular member.

In testimony whereof, I have hereunto subscribed my name this 14th day of J an., 1914;.

WILLIAM A. .DARRAH.

Witnesses:

Or'ro H. EsoHHoLz, I B. B. HINES.

Copies of this patent may be obtained for five guts each, by addressing the Commissioner of Patents, Washington, D. 0. 

